Chain link electric switch



Oct. 25, 1966 c. F. MAXTED ETAL 3,231,564

CHAIN LINK ELECTRIC SWITCH Filed Oct. 18, 1965 INVENTORS CHARLES F: MAXTED FRANCIS K80 URHE/VNE',

FIGJI.

A TTORNE'Y United States Patent O 3,281,564 CHAIN LINK ELECTRIC SWITCH Charles F. Maxted, 1130 W. Compton Blvd, Gardena, Calif., and Francis K. Bourhenne, 4171 W. 161st St., Lawndale, Calif.

Filed Oct. 18, 1965, Ser. No. 496,819 4 Claims. (Cl. 200-168) The present invention relates to an electric switch adapted to be incorporated in a link chain.

A lighting fixture of a type which may be positioned above a table is often held by a link chain having electric wires interwoven between the links. The present invention incorporates an electric switch in the linkage of novel form.

An object of the invention is to provide an electric switch particularly adaptable to link chains, which is so formed and constructed as not to detract from the appearance of the link chain but in appearance to form one of the links.

A further object is to provide an electrical switch for link chains which is easily operated without imposing undue stress on the switch or on the links of the chain.

A further object is to provide an electric switch of the character stated which is inexpensive in cost of manufacture, easily incorporated in a link chain, and in which all electric wire connections are easily made.

A further object is the provision of an electrical switch so fabricated as to have a minimum of parts and in which electric wires are easily connected thereto with a minimum of effort on the part of the installer, in that the installer does not need to remove the insulation from the electric wires to make electrical connection therewith.

In the drawing:

FIGURE 1 is a fragmentary, partially sectional view showing an overhead fixture secured by chain links, the chain of which incorporates the electric switch of the invention;

FIGURE 2 is a side elevation of the switch of the invention;

FIGURE 3 is an enlarged cross sectional view on the line 3-3 of FIGURE 2;

FIGURE 4 is a plan view of the interior of the switch showing the switch elements;

FIGURE 5 is a view similar to that of FIGURE 4 showing a second casing half;

FIGURE 6 is an enlarged sectional view on the line 66 of FIGURE 3;

FIGURE 7 is a transverse sectional view on the line 7-7 of FIGURE 3;

FIGURE 8 is a perspective view of one of the switch elements;

FIGURE 9 is a perspective view on an enlarged scale of one of the bus elements;

FIGURE 10 is a perspective view of a second bus element; and,

FIGURE 11 is a fragmentary, partially sectional diagrammatic wiring diagram for the switch.

Referring to the drawing, in FIGURE 1 is shown the general environment for the switch of the present invention wherein a fixture is designated as 1, chain links 2 being hooked as at 3 and 4 for the support of and adjustment as to height of the fixture. One end of the chain links 2 has connected thereto a switch 5 of the present invention. The switch 5 in turn through the medium of electric wiring 5a carries a plug 5b for insertion in an electrical socket 5c. The casing for the switch is of a size and shape which allows its insertion between links of a chain so that the switch appears as a further link of the chain 2. It is to be particularly noted that the switch location is chosen ,so as not to impose the weight of the fixture 1 thereon although the switch is of a strength which would permit its use in locations to sustain weight. The switch 5 has a casing formed in two parts 6 and 7 as shown in FIGURE 3, the two parts being of identical form and construction. The switch casing is substantially of ovoid form, each casing part 6 and 7 having a convex outer surface 8 and a substantially fiat or plane inner surface 9. The marginal edge 10 between the convex and the plane surfaces for each casing part is substantially plane and at a right angle to the plane surface 9. Ends of each casing part are grooved at 11 and 12. Transverse bores 13 and 14 are provided at the grooved portions, the bores of each casing part matching so as to receive a chain link through pairs of bores as shown by the dotted links 15 and 16 in FIGURE 2. When the cas ing parts are matched, the casing parts are held in position by a pin 17 carried by each casing part and extending above the plane surface thereof for reception in an opening in each plane part as shown at 18. An elongated screw 19 is passed through aligned bores in each casing part, as shown in FIGURE 3, at 20 and 21, the screw being secured by a nut 22 and the head of the screw plus the nut being received in countersunk bores 23 and 24. Thus, one screw and nut holds both parts of the casing in juxtaposition and in working relationship.

Each :half of the switch casing is of identical construction and, hence, one of said halves will be described, the same numbers of reference likewise applying to the other half of the casing. The casing half 6 is detailed in FIG- URE 4 and casing half 7 in FIGURE .5. Casing half 6 is provided on its plane surface with an elongated groove 30 which extends between its curved marginal ends, with a barrier wall 31 dividing the groove length. Groove 30 is for the purpose of receiving insulated wires as illustrated at 32 and 33. The barrier wall limits the degree of insertion of each wire 32 and 33 within the groove. Positioned within grooves inwardly of the plane surface 9 are electrical contact straps 34 and 35 formed from any electrical conductive material such as spring brass. The contact strap 34 shown in FIGURE 9, includes a fiat portion 38 intermediate acute angle portions 39 and 40. The portion 39 is of narrower width than the flat portion 38 and is provided with a curved end 41. The portion 40 has substantially the same width as the portion 38. Part 40 is joined with portion 42 which is U-shaped and provides two parallel members 43 and 44 in spaced apart relationship, the member 44 is joined with portion 45 extending at an acute angle to member 44. Portion 42 and particularly the member 43 has a side extension 46 lying in the plane of the portion 43 and which extension is joined to a pointed spur portion 47 by a connecting piece 48. The pointed spur 47 is at an obtuse angle to the portion 46. The plane portion 38 is provided with two spaced apart depressions or dimples 49 and 50, the purpose of which will be detailed in the statement of operation.

The second contact strap shown in FIGURE 10 and designated as 35, includes a strap bent to provide an intermediate portion 60 having two end portions 61 and 62 at an obtuse angle to portion 60. Portion 61 joins a part 63 at an acute angle while part 62 joins the portion 64 which parallels portion 60, portion '64 being provided with a part 65 at a right angle to portion 64 and with a con- 3 necting portion 66 joining with a pointed spur 67, the pointed spur being at an acute angle to the connecting portion 66. 1Portion 60 is punched to have .a tongue 68 rising above portion 60.

Each casing half is formed to receive the contact straps 34 and 35. Referring to FIGURE 6, it will be observed that contact straps of the type shown in FIGURE 9 are received within groove portions which face inwardly from the plane surface of each casing half. Thus, to accommodate the strap of FIGURE 9, each casing half is provided with elongated groove 70 and with a ledge or shoulder surrounding groove 70. This construction provides parallel walls at 72 and 73 bounding the ledge 71. A wall 74 bridges groove 70 resulting in a groove at 75. This type of grooving for both parts of the casing is such as to adequately position the contact strap 34 Within the same and the strap is placed within groove 70 so that the portion 38 parallels the base 79 of the groove as shown in FIGURE 6 with the end portions 39 and 40 engaging said base 79 as shown at 80 and 81. It will be noted upon reference to FIGURE 6 that the length of the groove is greater than the distance between points of contact of the strap with said base as shown at 80 and 81 and, therefore, the top or plane portion 38 may flex downwardly under pressure. The U-shaped portion 42 embraces the wall 74 to hold this portion of the strap in position and the portion 45 is received within the groove 75 in such a manner as to frictionally engage the wall bounding said groove and to generally hold the strap against displacement. The portion 46 which carries the pointed spur is passed through a groove 85 into groove 86. This groove has within the same an upstanding pin 87 and the spur passes at one side of said pin and into the space which would be occupied by the insulated wire as shown in FIGURE 4.

The second contact strap 35 is confined within a groove 90 separated from and paralleling groove 70, which groove is bounded by the wall 73 and an interrupted wall 91. This construction perm-its insertion of the strap 35 within the groove 90 so that the foot portions, being the portions at the ends of the straps 61 and 62 may engage the base surface for said .groove in the same manner as provided for the strap of FIGURE 9. This spaces the tongue 68 upwardly and outwardly of the plane surface of the casing half while the spur 67 extends outwardly and downwardly into the groove which receives one of the insulation wires as shown in FIGURE 5. The portion 65 of the strap abuts a bounding wall for the groove 90, as shown in FIGURE 4 .and thus prevents shifting movement of said strap.

Each marginal wall 72 is relieved or notched at 94, FIGURE 5, to receive a slider contact member 100 of the type shown in FIGURE 8.

The slider 100, includes a body which is substantially a rectangular parallelepiped in form, having faces 101 and 102, with a transverse bore 103 extending between said faces and with aligned bulbous enlargements 104 on each face. A finger piece 105 is carried on the face 106 by a reduced width spacer member 107, the construction being such that a way is provided with the finger piece 105 and the face 106, as shown in FIGURE 8. The way between the finger piece and body 100 is such that the device may be received in the notched portions 94 and for slide movement relative to the flanges 72 and, likewise, guided by said flanges during said movement.

The bore 103 is adapted to receive an electrically conductive ball 110, the diameter of the ball being slightly greater than the width of the body.

The finger piece is provided with a concavity 111a provided with lateral serrations 111.

The operation, uses and advantages of the invention are as follows.

URES 9 and 10 within their respective grooves for each half of the casing, the slider having an electrically conductive ball, is placed between the two halves of the casing at the marginal edges of flange 72 so that the slider lies between two contact straps 34. The indentations 49 and 50 for each contact strap are so spaced that the bulbular enlargements 104 carried by the slider will engage said depressions sequentially depending on movement thereof to so posit-ion the ball as to bridge said electrical contacts, as shown in FIGURE 6 or to move from said position to the dotted line position for said ball, as shown in FIGURES 6 and 11, the ball being out of contact with one of said electrical conducting straps. The straps 35, when the two facing parts are in juxtaposition, have the tongue portions 68 in engagement, as for instance illuslustrated in FIGURE 11. The pins and the holes 17 and 18 respectively maintain alignment of the two casing parts and the bolt and nut assembly between the two casing parts holds the casing parts together, as shown in FIG- URE 3.

The construction shown is particularly adaptable for chain links which have an electrical wire woven between the links to a fixture, as the links may be readily passed through the openings 13 and 14. An electrical circuit through the switch is completed by providing dual insulated wires passed inwardly of the wire receiving bores 30 as shown in FIGURES 4 and 5. As an example, each pair of wires and its insulation are cut flush, and the flush ends moved inwardly of grooves 30 to wall 31. The spurs will slide on the insulation as the Wires move inwardly of the casing and will penetrate the insulation and contact the wires as the wires are pulled outwardly of the casing, forcing the wires and the insulation into relieved areas and 121 for each casing part as the pointed spurs swing on an arc. It thus becomes evident that it is simple to wire the switch either before or after it is connected with the links of the chain. The electrically conductive ball 110 is easily confined within the bore 103 by upsetting the bore, as shown in FIGURE 8, at 125 and likewise by providing a ball having a diameter slightly greater than the width of the slot 70. Thus, a hell, even if allowed free movement transversely within the bore 103, would nevertheless not escape from said bore so as to prevent movement of the slide and the making and breaking of an electric contact.

It has been found that the slider moves easily and without causing any twist which often results from the use of a lever type switch. Lever type switches usually require both hands, one hand to hold the casing and the other hand to move the lever whereas with the present device a finger may move the slider very easily.

We claim:

1. An electric switch adapted to be included as a link in a link chain, including: a two-part casing each part being of identical form; each part housing first and second electrical contact straps; each contact strap provided with a pointed spur, each casing part provided with an electric wlre receiving groove and said pointed spurs projecting into said grooves; said parts when in juxtaposition positioning the first contact straps and the second contact straps in overlying parallel relationship and said second contact straps provided with means adapted to co-eng-age when in said overlapped relationship to provide an electrical path therebetween, a slider provided with an electrically conductive ball interposed between the pair of first contact straps and for rolling contact therewith, said ball bridging the first contact straps to complete an electrical circuit when the slider is in one position and to break electrical contact between said contact straps when the slider is moved to a second position to break bridging engagement by the ball between the contact straps.

2. The device as set forth in claim 1, said electric wire receiving grooves for each casing half being complementary when the casing parts are in juxtaposition and adapted to receive two insulated electric wires, pairs of said pointed spurs adapted to penetrate said insulation for separate contact with the electric wires of said pairs 4. The device of claim 1, said electric wire receiving to complete a series electrical connection with separate grooves of the casing adapted to receive severed ends of insulated pairs of wires inserted within said grooves at two separate insulated two-conductor wire cable for each end of the casing. penetration of the insulation by pairs of said pointed spurs 3. The device as set forth in claim 1, said cont-act slider 5 and for contact with the electric wires.

including a body and a fingerpiece, there being a way between the body and fingerpicce and each casing half NO references citedformed with an interrupted flange portion for reception in the way of said slider for guiding movement of the ROBERT SCHAEFER P'lmary Examme' slider. 10 D. SMITH, JR., Assistant Examiner. 

1. AN ELECTRIC SWITCH ADAPTED TO BE INCLUDED AS A LINK IN A LINK CHAIN, INCLUDING: A TWO-PART CASING EACH PART BEING OF IDENTICAL FORM; EACH PART HOUSING FIRST AND SECOND ELECTRICAL CONTACT STRAPS; EACH CONTACT STRAQP PROVIDED WITH A POINTED SPUR, EACH CASING PART PROVIDED WITH AN ELECTRIC WIRE RECEIVING GROOVE AND SAID POINTED SPURS PROJECTING INTO SAID GROOVES; SAID PARTS WHEN IN JUXTAPOSITION POSITIONING THE FIRST CONTACT STRAPS AND THE SECOND CONTACT STRAPS IN OVERLYING PARALLEL RELATIONSHIP AND SAID SECOND CONTACT STRAPS PROVIDED WITH MEANS ADAPTED TO CO-ENGAGE WHEN IN SAID OVERLAPPED RELATIONSHIP TO PROVIDE AN ELECTRICAL PATH THEREBETWEEN, A SLIDER PROVIDED WITH AN ELECTRICALLY CONDUCTIVE BALL INTERPOSED BETWEEN THE PAIR OF FIRST CONTACT STRAPS AND FOR ROLLING CONTACT THEREWITH, SAID BALL BRIDGING THE FIRST CONTACT STRAPS TO COMPLETE AN ELECTRICAL CIRCUIT WHEN THE SLIDER IS IN ONE POSITION AND TO BREAK ELECTRICAL CONTACT BETWEEN SAID CONTACT STRAPS WHEN THE SLIDER IS MOVED TO A SECOND POSITION TO BREAK BRIDGEING ENGAGEMENT BY THE BALL BETWEEN THE CONTACT STRAPS. 